/**
* \file aes_keyschedule.c
* \email daniel.otte@rub.de
- * \author Daniel Otte
+ * \author Daniel Otte
* \date 2008-12-30
* \license GPLv3 or later
- *
+ *
*/
#include <stdint.h>
#include <avr/pgmspace.h>
static
-void aes_rotword(void* a){
+void aes_rotword(void *a){
uint8_t t;
t=((uint8_t*)a)[0];
((uint8_t*)a)[0] = ((uint8_t*)a)[1];
((uint8_t*)a)[3] = t;
}
-uint8_t rc_tab[] PROGMEM = { 0x01, 0x02, 0x04, 0x08,
+const uint8_t rc_tab[] PROGMEM = { 0x01, 0x02, 0x04, 0x08,
0x10, 0x20, 0x40, 0x80,
0x1b, 0x36 };
-void aes_init(const void* key, uint16_t keysize_b, aes_genctx_t* ctx){
+void aes_init(const void *key, uint16_t keysize_b, aes_genctx_t *ctx){
uint8_t hi,i,nk, next_nk;
uint8_t rc=0;
- uint8_t tmp[4];
+ union {
+ uint32_t v32;
+ uint8_t v8[4];
+ } tmp;
nk=keysize_b>>5; /* 4, 6, 8 */
hi=4*(nk+6+1);
memcpy(ctx, key, keysize_b/8);
next_nk = nk;
for(i=nk;i<hi;++i){
- *((uint32_t*)tmp) = ((uint32_t*)(ctx->key[0].ks))[i-1];
+ tmp.v32 = ((uint32_t*)(ctx->key[0].ks))[i-1];
if(i!=next_nk){
if(nk==8 && i%8==4){
- tmp[0] = pgm_read_byte(aes_sbox+tmp[0]);
- tmp[1] = pgm_read_byte(aes_sbox+tmp[1]);
- tmp[2] = pgm_read_byte(aes_sbox+tmp[2]);
- tmp[3] = pgm_read_byte(aes_sbox+tmp[3]);
+ tmp.v8[0] = pgm_read_byte(aes_sbox+tmp.v8[0]);
+ tmp.v8[1] = pgm_read_byte(aes_sbox+tmp.v8[1]);
+ tmp.v8[2] = pgm_read_byte(aes_sbox+tmp.v8[2]);
+ tmp.v8[3] = pgm_read_byte(aes_sbox+tmp.v8[3]);
}
} else {
next_nk += nk;
- aes_rotword(tmp);
- tmp[0] = pgm_read_byte(aes_sbox+tmp[0]);
- tmp[1] = pgm_read_byte(aes_sbox+tmp[1]);
- tmp[2] = pgm_read_byte(aes_sbox+tmp[2]);
- tmp[3] = pgm_read_byte(aes_sbox+tmp[3]);
- tmp[0] ^= pgm_read_byte(rc_tab+rc);
+ aes_rotword(&(tmp.v32));
+ tmp.v8[0] = pgm_read_byte(aes_sbox+tmp.v8[0]);
+ tmp.v8[1] = pgm_read_byte(aes_sbox+tmp.v8[1]);
+ tmp.v8[2] = pgm_read_byte(aes_sbox+tmp.v8[2]);
+ tmp.v8[3] = pgm_read_byte(aes_sbox+tmp.v8[3]);
+ tmp.v8[0] ^= pgm_read_byte(rc_tab+rc);
rc++;
}
((uint32_t*)(ctx->key[0].ks))[i] = ((uint32_t*)(ctx->key[0].ks))[i-nk]
- ^ *((uint32_t*)tmp);
+ ^ tmp.v32;
}
}
-void aes128_init(const void* key, aes128_ctx_t* ctx){
+void aes128_init(const void *key, aes128_ctx_t *ctx){
aes_init(key, 128, (aes_genctx_t*)ctx);
}
-void aes192_init(const void* key, aes192_ctx_t* ctx){
+void aes192_init(const void *key, aes192_ctx_t *ctx){
aes_init(key, 192, (aes_genctx_t*)ctx);
}
-void aes256_init(const void* key, aes256_ctx_t* ctx){
+void aes256_init(const void *key, aes256_ctx_t *ctx){
aes_init(key, 256, (aes_genctx_t*)ctx);
}